(Pulled from 2008(2018) archive. (no reply))
I (still) think that a Replace_Text search-only feature, as separate user-right, could be useful.
Especially due to the fact that the normal MW search feature is more targeted in its functionality at wiki visitors, and not at general editors. (that's at least my POV on MW's normal search feature)
That way the search-only feature could be given to active editors to help them in finding potential additional edit targets. (leaving the real global changes still in the hands of higher level users)